Proper management of foraging areas is important to maximize animal carrying capacity, encourage animal vitality/health, and to preserve the environment. Three issues facing those who manage foraging areas include (1) the location of wild ungulate foraging, (2) the proliferation of noxious plants, including those plants classified as an invasive species, and (3) the existence of herbaceous fuels in areas susceptible to wildfires.
With respect to the first issue facing those who manage foraging areas, wild ungulates, such as elk, deer, bison, etc., forage where they find foraging conditions to be most suitable. Consequently, the natural foraging distribution of wild ungulates may encompass some foraging areas and not others. Thus, some foraging areas will have many wild ungulates, while other foraging areas will have few or none.
Individuals and groups, such as ranchers, farmers, wildlife enthusiasts, environmentalists, state and national wildlife agencies, and state and national land management agencies, concern themselves with the natural foraging distribution of wild ungulates in various foraging areas. For example, farmers prefer that the foraging distribution of wild ungulates does not encompass their fields when their crops are first sprouting in the springtime. To prevent the transmission of disease from wild ungulates to livestock, as can occur between bison infected with brucellosis and cattle, ranchers prefer that the foraging distribution of wild ungulates does not encompass the grazing area of their livestock. Wildlife enthusiasts and park managers prefer that the foraging distribution of wild ungulates encompasses less remote areas to facilitate the viewing of wild ungulates, thereby increasing appreciation for wild ungulates and nature.
In view of the preceding discussion, it is clear that there is a need in the art for a method of modifying the natural foraging distribution of wild ungulates.
With respect to the second issue facing those who manage foraging areas, noxious weeds, and especially non-native noxious weeds or invasive plant species, have become a significant problem throughout North America and other parts of the world. A plant becomes an invasive specie by being transferred through artificial means (usually human action) to locations where the plant has no natural inhibitors to the plant's proliferation (e.g., the location lacks animals that naturally graze the plant, diseases or insect enemies that naturally afflict the plant, etc.). A classic example of an invasive species is the prickly pear (Opuntia stricta), which overran vast areas of Australia until a moth (Cactoblastis cactorum) was introduced, eliminating more than 90% of the prickly pear infestation within 10 years.
Invasive species disturb natural ecosystems, displacing species native to the location and causing harm. In some areas, invasive plant species have resulted in an environmental disaster, wherein one or more invasive plant species have crowded out native plants to the point of extinction. For example, in parts of western Montana, spotted knapweed (Centaurea maculosa) has spread to the point that some areas are nearly devoid of native grasses. A similar situation exists in southwest South Dakota and northeast Wyoming with respect to leafy spurge (Euphorbia esula).
Once established in an area, invasive plant species quickly spread and crowd out native plant species. As result, native plant species are significantly reduced or made extinct in the area, thereby reducing the area's ability to support wild and domestic animals that depend on the native plant species for food and shelter.
Chemical herbicides are useful in the control, reduction and eradication of noxious weeds, including invasive species. However, because plant seeds often fall to the ground and delay sprouting for several years, chemical herbicides, and all other weed control methods, must be faithfully applied year after year in an area to control, reduce and eventually eradicate the noxious weeds. Where the areas of noxious weed infestation are great in size and concentration, the repeated application of herbicides can be very expensive. For example, it is estimated Missoula County, in western Montana, has over 600,000 acres of noxious weeds and that it would take $12 to $14 million per year from 2005 to 2020 to eradicate the county's noxious weeds. Not only is such an effort cost prohibitive, but the application of such large and continuous amounts of chemical herbicide would likely have adverse environmental and health consequences.
To avoid the cost, health and environmental drawbacks associated with combating spotted knapweed via chemical herbicides, Missoula County has turned other methods of weed control including the introduction of biological control agents, seeding with weed resistant grasses, inter-seeding weedy areas, and controlled grazing with ungulates, such as cattle, sheep and goats. Each of these methods of weed control has its own drawbacks. For example, with respect the two seeding methods, plant seed is very expensive to purchase and plant. This expense can be cost prohibitive when having to seed large areas annually.
With respect to the biological control agent method, Missoula County has introduced the knapweed seed head fly (Urophora affinis and U. quadrifasciata), the lesser nap weed flower weevil (Larinus minutus), the knapweed root weevil (Cyphocleonus acbates), and the yellow winged knapweed root weevil (Agapeda zoegana). Each of these insects naturally afflicts spotted knapweed. However, introducing such biological control agents has risks of its own where the biological control agent is non-native and, as a result, could itself become an invasive species.
With respect to the grazing methods, ungulates (e.g., cattle, sheep and goats) will graze on spotted knapweed during certain stages of the plant's existence. To achieve any weed control benefit from the ungulates' willingness to graze upon spotted knapweed, herders have been employed to maintain the ungulates in the spotted knapweed areas of a grazing area in order to get the ungulates to sufficiently focus their grazing activities on the spotted knapweeds. Unfortunately, herding is very labor intensive. Also, ungulates are adverse to being pushed or forced into a spotted knapweed patch in the spotted knapweed areas of a pasture, thereby making it difficult to achieve optimum weed control benefit from concentrating the ungulates on the spotted knapweed patches.
In view of the preceding discussion, it is clear that there is a need in the art for a method of controlling noxious plant species that is safe, cost effective, of low labor intensity, and optimizes the control, reduction and eventual eradication of the noxious plant species.
With respect to the third issue facing those who manage foraging areas, wildfires are an ever increasing concern. These concerns relate not only to the occurrence of fire, but also the costs of fighting them. A recent five-part Los Angeles Times series on the costs and futility of fighting fires won a Pulitzer Prize. “In their wildfire articles, reporters Bettina Boxall and Julie Cart reported that costly aerial drops of water and retardant often were ordered against firefighters' better judgment because they “make good television” and helped win political points for local officials.” Susman, Tina, “Pulitzers recognize the public watchdogs,” Los Angeles Times, Apr. 21, 2009. “The tab for one day of fire fighting was more than $2.5 million. Despite such expenses, the series showed, fire protection policies were not working, and bigger, deadlier fires were raging.” Id. In light of these futile efforts and their associated costs, an alternative and more proactive approach is needed.
One known problem or factor in the fuels available for forest fires relates to the tendency, mentioned above, of wild ungulates to forage where they find foraging conditions to be most suitable. This may leave many non-cultivated areas overgrown. One of these tendencies, which may exacerbate the problem, may be for wild ungulates to prefer new sprouting growth, leaving cured growth untouched and increasingly susceptible to wild fires. The tendency to forage in suitable areas is seen in domestic ungulates as well, where they may focus on lowland riparian areas. This tendency may also exacerbate the problem of wildfires because the highland areas, which may be naturally drier, are the areas that may become overgrown. In addition to the natural tendency of ungulates to forage where it is most suitable, the infiltration of noxious and/or invasive plant species may cause ungulates, wild or domestic, to avoid additional areas of potential foraging. Consequently, these overgrowth areas may be susceptible to wildfires. This may be especially true during dry conditions.
In view of the preceding discussion, it may be apparent that there is a need in the art for a method of controlling ungulate grazing patterns to reduce herbaceous fuels in areas susceptible to wild fires.